Re: [APML] Another M3 from the dark side

[Radu Corlan <rcorlan@pcnet.ro>]

On Mon, 26 May 2003, Paul M. Rybski wrote:

> Dear Radu,
> 
>       Your images appear to show a complex, radially and azimuthally 
> dependent comatic aberration.  Any explanation for it?  It doesn't 
> appear to be a guiding problem.

There is a guiding component in the WNW - ESE direction, but small.

Another thing i'm thinking about is some miscollimation; that could 
explain why stars in the top-right corner are worse than others.

Yet another thing i'm thinking about is the possibility that the camera is 
tilted. The setup is LX200->6.3reducer->NGF focuser->camera. I've seen the 
same problem in other pictures taken with the same setup. However, i 
checked parallelisn carefully, and it's always the upper-right corner 
that's the worst. I think it's improbable that the mislignment be always 
in the same spot.

Radu

> 
> Paul
> 
> 
> 
> >Last week i took some V and I images of M3 with the intention of making
> >a Hertzspung-Russel diagram of the cluster. Happily, the seeing was 
> >good, and the images turned quite good, so i've posted them at
> >
> >http://astro.corlan.net/ccd/index.html
> >
> >The links are at the top of the page.
> >
> >Radu
> >
> >--
> >Astronomy page: http://astro.corlan.net
> >-------------
> >Radu Corlan       Snail Mail: Bucuresti sect. 1,
> >rcorlan@pcnet.ro  str. Argentina nr. 28, Romania
> >
> >    You can still escape the "Gates" of Hell!  
> >                  Use Linux!                      
> >
> >
> >_______________________________________________
> >Astro-Photo mailing list
> >Astro-Photo@seds.org
> >http://seds.org/mailman/listinfo/astro-photo
> 
> 
> ________________________________________
> Paul M. Rybski, Ph.D.
> Associate Professor and Acting Chair, Dept. of Physics, and
> Director, Whitewater Observatory
> Goodhue 320
> University of WI-Whitewater
> Whitewater, WI  53190-1790
> 
> Office FAX:     (262) 472-5633
> Email address:  rybskip@uww.edu
> 

-- 

-------------
Radu Corlan       Snail Mail: Bucuresti sect. 1, 
rcorlan@pcnet.ro  str. Argentina nr. 28, Romania

   You can still escape the "Gates" of Hell!   
                 Use Linux!                       


_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo